The ExampleViewer component was extracting only innerHTML from code
blocks in multifile examples, which lost the shell class applied by
the formatCode function. This caused the $ prompt to not appear for
shell commands in multifile blocks even when language="shell" was set.
Modified the Snippet interface to track shell language state and
updated getCodeSnippetsFromMultifileWrapper and getStandaloneCodeSnippet
methods to preserve the shell class. Updated example-viewer template
to conditionally apply the shell class to the code wrapper element.
Fixes inconsistency between standalone and multifile shell code blocks.
To increase the ease of development we are moving @angular/docs into the adev directory within this repo. While
we are doing this to improve our development experience in the short term, efforts are also in place
to maintain a division between this @angular/docs (shared) code and adev itself, so that it can be extracted
back out in the future when components is ready to leverage it as well.
PR Close#57132
